sonata 无法调节 oss 音量

# from http://bbs.archlinux.org/viewtopic.php?id=88570

mixer_type "software"

audio_output 
{

 type "oss"
 name "My OSS Device"
 mixer_control "PCM" # optional
 format "44100:16:2" # optional

 device "/dev/dsp" # optional
 mixer_device "/dev/mixer" # optional

 # From http://bbs.archlinux.org/viewtopic.php?id=55438

 #device "/dev/oss/oss_hdaudio0/pcm0"
 #mixer_device "/dev/oss/oss_hdaudio0/pcm0"

}

Device objects
 0: osscore0 OSS core services
 1: oss_hdaudio0 Intel HD Audio interrupts=353975 (372469)
 HD Audio controller Intel HD Audio
 Vendor ID 0x8086293e
 Subvendor ID 0x1043829f
 Codec 0: ALC883 (0x10ec0883/0x1043829f)
 2: oss_usb0 USB audio core services

MIDI devices (/dev/midi*)

Mixer devices
 0: High Definition Audio ALC883 (Mixer 0 of device object 1)

Audio devices
HD Audio play front /dev/oss/oss_hdaudio0/pcm0 (device index 0)
HD Audio play rear /dev/oss/oss_hdaudio0/pcm1 (device index 1)
HD Audio play center/LFE /dev/oss/oss_hdaudio0/pcm2 (device index 2)
HD Audio play side /dev/oss/oss_hdaudio0/pcm3 (device index 3)
HD Audio play pcm4 /dev/oss/oss_hdaudio0/pcm4 (device index 4)
HD Audio play spdif-out /dev/oss/oss_hdaudio0/spdout0 (device index 5)
HD Audio rec mix /dev/oss/oss_hdaudio0/pcmin0 (device index 6)
HD Audio rec mix /dev/oss/oss_hdaudio0/pcmin1 (device index 7)

Nodes
 /dev/dsp -> /dev/oss/oss_hdaudio0/pcm0
 /dev/dsp_in -> /dev/oss/oss_hdaudio0/pcm0
 /dev/dsp_out -> /dev/oss/oss_hdaudio0/pcm0
 /dev/dsp_ac3 -> /dev/oss/oss_hdaudio0/spdout0
 /dev/dsp_mmap -> /dev/oss/oss_hdaudio0/pcm0
 /dev/dsp_multich -> /dev/oss/oss_hdaudio0/pcm0